MEMS-based devices may use deposited polycrystalline or amorphous materials to form compliant regions. The compliant regions may be defined using a combination of photolithographic techniques along with selective dry or wet etching to pattern various compliant spring geometries in order to meet the particular application requirements. These techniques may be used to define either a single set of springs attached to a portion of a proof mass surface or dual sets of springs attached to top and bottom regions of a proof mass. However, the performance of the formed spring-mass system is impacted by the exact deposition thickness of the material, deposition thickness uniformity across a sensor design, stress of the deposited material, and surface roughness of the deposited material. Additionally, amorphous and polycrystalline springs tend to suffer from mechanical creep over time, thus changing the characteristics under which they act under an applied external force.
Alternatively, other MEMS designs may utilize a timed wet or dry etch of bulk crystalline silicon to define a thin complaint single crystal suspension system. The etching can occur from the front, back or front and back of a single crystal wafer to form the desired compliant region. The drawback to these techniques is that because they rely on a timed etched, the thickness of the resultant compliant region can be impacted and therefore the spring constant is not as predicted or designed. In addition, the etches used to define the compliant regions are not ideal and can lead to surface roughness, thereby impacting the quality of the compliant region.